For those waiting to find out what happens when Strikeforce heavyweight champion Alistair Overeem faces top-level competition, well, patience is a virtue.

Overeem (34-11, 1 no contest) has destroyed mostly second-rate competition in MMA while also finishing some of the biggest names in heavyweight kickboxing since morphing in recent years from a skinny light heavyweight to someone who looks like a character in a Justice League comic book.

In what was the most anticipated first-round match of the Strikeforce Heavyweight Grand Prix tournament, Overeem was to meet Fedor-slayer Fabricio Werdum (14-4-1) on April 9 as part of the second leg of first-round matches.

Issues involving Josh Barnett, who is unlicensed in California due to a failed steroid test, helped postpone the next event in the Strikeforce Grand Prix.

But on Tuesday night, Strikeforce CEO Scott Coker confirmed the tournament date will be moved back and the April 9 event will proceed without Grand Prix matches. The final two first-round matches now will take place on June 18 at the American Airlines Center in Dallas.

The change came for a number of reasons, but in the end, the biggest problems were licensing issues involving Josh Barnett (26-5), who faces Brett Rogers (11-2) in the tourney’s other fight.

When the Grand Prix was first announced, Barnett’s name raised eyebrows with MMA insiders, since his toughest battles in recent years have not been in the cage but with the California State Athletic Commission.

He failed a steroid test in the summer of 2009 – the third of his career – before he was scheduled to face Fedor Emelianenko in an Affliction show that was completely canceled. Since then, Barnett has had numerous hearings with the California commission that have gone nowhere, and he remains unlicensed.

Many of the major state commissions, such as New Jersey and Nevada, would not allow him to fight until California cleared him. But Coker noted a number of states, Texas being among the most prominent, were fine with licensing Barnett provided he passed a steroid test before his fight.

Barnett is a well-rounded fighter who proved in the Pride days that he could compete at the top level. But like Overeem, he has been somewhat untested in his last six fights, all of which he has won. His last major test was a fight against a prime version of Antonio Rodrigo Nogueira, but that was back in 2006, which in this sport is a different era.

Regarding the delay, Coker said, “We had so much success with our last show, we set a record on Showtime, we had our fastest advance sales, that we wanted to continue our momentum and run in a major market and a top arena. We also wanted to have time to correctly promote the show so that we can do the same type of numbers.

“But the major arenas have NHL and NBA commitments this time of the year, and the only major arenas we could confirm were in California. One of our fighters isn’t licensed in California. So last week I made the call to postpone it.”

The first tournament show, held Feb. 12 at the Izod Center in East Rutherford, N.J., where Antonio Silva upset Emelianenko and Sergei Kharitonov knocked out Andrei Arlovski, set Showtime records for an MMA event with 741,000 viewers and for highest rated single fight, with the Emelianenko-Silva doing a 3.2 rating and 1.1 million viewers. Those numbers beat records set in 2009 for the Gina Carano-Cris “Cyborg” Santos match.

The Dallas show will feature three matches along with the two tournament bouts. “King” Mo Lawal has confirmed his participation. Coker also said the return of Carano after what would be nearly two years away from the sport also is possible for that date.

Coker said the tournament would still finish before the end of the year, with the semifinals set for September and the finals in December. But those dates aren’t etched in stone as fighters must be healthy. Plus, if Barnett, who would be favored against Rogers, doesn’t get cleared in California and isn’t eliminated from the tournament, the tourney could face arena-booking issues later in the year.

Also confirmed were lightweight champion Gilbert Melendez (19-2) and welterweight champ Nick Diaz (24-7, 1 no contest), who would have title defenses for the new version of the April 9 Showtime event from the Valley View Casino Center (formerly the Sports Arena) in San Diego.

Melendez will face Tatsuya “The Crusher” Kawajiri (27-6-2), who earned the title shot by beating then-top contender Josh Thomson on the New Year’s Eve show in Saitama, Japan. The two have similar styles, with both fast-paced boxing and some power wrestling thrown in. The two fought on the 2006 New Year’s Eve show, with Melendez winning a decision in one of that year’s best matches, but both are more seasoned against top-level competition today.

Diaz will face Paul Daley (27-9) in a battle of the sport’s controversial figures. Diaz’s track record includes a couple of post-fight brawls, one of which is a key reason Strikeforce hasn’t been back on CBS, as well as controversies over marijuana testing.

Daley, who has some of the best hands in the welterweight division, was kicked out of the UFC last year for throwing a sucker punch after losing what ended up as a wrestling match with Josh Koscheck, which was to determine a title shot at Georges St. Pierre. In Diaz, he’ll face someone with quick hands and great conditioning, known for an incredible punch output. Daley has a weakness on the ground, and while Diaz has top level jiu-jitsu skills, it’s not a lock that he could easily take Daley down.

Since then, the British fighter has won four in a row, including this past Saturday in Manchester, U.K., knocking out Yuya Shirai, the welterweight champion of the Deep organization in Japan. But Daley, who overwhelmed Shirai in just 1:46, missed making weight in what was to be a championship fight for the U.K.-based BAMMA organization. He first weighed in at 172 pounds, and then on his second try, got down to 170.9 pounds. It was the third time in recent years that he missed weight. Even though it’s a short turnaround, Daley jumped at the chance to take the title fight, according to Coker.

The main card also will include a light heavyweight bout with Mike Kyle (18-8-1, 1 no contest) against current Dream champion and former Strikeforce champion Gegard Mousasi (30-3-1). Kyle, a regular training partner of UFC heavyweight champion Cain Velasquez, nearly finished Silva in the first round of his last fight on Dec. 4 in St. Louis, before losing in the second. Kyle also has a 2009 knockout win over current Strikeforce champion Rafael “Feijao” Cavalcante.

The bout would seem to create a natural contender for the winner of Saturday’s title match from Columbus, Ohio, where Cavalcante defends against Dan Henderson.